return rhs;
}
-/* Simple linked list, describing known contents of an aggregate beforere
+/* Simple linked list, describing known contents of an aggregate before
call. */
struct ipa_known_agg_contents_list
struct ipa_known_agg_contents_list *next;
};
-/* Find the proper place in linked list of ipa_known_agg_contents_list
- structures where to put a new one with the given LHS_OFFSET and LHS_SIZE,
- unless there is a partial overlap, in which case return NULL, or such
- element is already there, in which case set *ALREADY_THERE to true. */
+/* Add a known content item into a linked list of ipa_known_agg_contents_list
+ structure, in which all elements are sorted ascendingly by offset. */
-static struct ipa_known_agg_contents_list **
-get_place_in_agg_contents_list (struct ipa_known_agg_contents_list **list,
- HOST_WIDE_INT lhs_offset,
- HOST_WIDE_INT lhs_size,
- bool *already_there)
+static inline void
+add_to_agg_contents_list (struct ipa_known_agg_contents_list **plist,
+ struct ipa_known_agg_contents_list *item)
{
- struct ipa_known_agg_contents_list **p = list;
- while (*p && (*p)->offset < lhs_offset)
+ struct ipa_known_agg_contents_list *list = *plist;
+
+ for (; list; list = list->next)
{
- if ((*p)->offset + (*p)->size > lhs_offset)
- return NULL;
- p = &(*p)->next;
+ if (list->offset >= item->offset)
+ break;
+
+ plist = &list->next;
}
- if (*p && (*p)->offset < lhs_offset + lhs_size)
+ item->next = list;
+ *plist = item;
+}
+
+/* Check whether a given known content is clobbered by certain element in
+ a linked list of ipa_known_agg_contents_list. */
+
+static inline bool
+clobber_by_agg_contents_list_p (struct ipa_known_agg_contents_list *list,
+ struct ipa_known_agg_contents_list *item)
+{
+ for (; list; list = list->next)
{
- if ((*p)->offset == lhs_offset && (*p)->size == lhs_size)
- /* We already know this value is subsequently overwritten with
- something else. */
- *already_there = true;
- else
- /* Otherwise this is a partial overlap which we cannot
- represent. */
- return NULL;
+ if (list->offset >= item->offset)
+ return list->offset < item->offset + item->size;
+
+ if (list->offset + list->size > item->offset)
+ return true;
}
- return p;
+
+ return false;
}
/* Build aggregate jump function from LIST, assuming there are exactly
- CONST_COUNT constant entries there and that th offset of the passed argument
+ CONST_COUNT constant entries there and that offset of the passed argument
is ARG_OFFSET and store it into JFUNC. */
static void
}
}
+/* If STMT is a memory store to the object whose address is BASE, extract
+ information (offset, size, and value) into CONTENT, and return true,
+ otherwise we conservatively assume the whole object is modified with
+ unknown content, and return false. CHECK_REF means that access to object
+ is expected to be in form of MEM_REF expression. */
+
+static bool
+extract_mem_content (gimple *stmt, tree base, bool check_ref,
+ struct ipa_known_agg_contents_list *content)
+{
+ HOST_WIDE_INT lhs_offset, lhs_size;
+ tree lhs, rhs, lhs_base;
+ bool reverse;
+
+ if (!gimple_assign_single_p (stmt))
+ return false;
+
+ lhs = gimple_assign_lhs (stmt);
+ rhs = gimple_assign_rhs1 (stmt);
+
+ if (!is_gimple_reg_type (TREE_TYPE (rhs))
+ || TREE_CODE (lhs) == BIT_FIELD_REF
+ || contains_bitfld_component_ref_p (lhs))
+ return false;
+
+ lhs_base = get_ref_base_and_extent_hwi (lhs, &lhs_offset,
+ &lhs_size, &reverse);
+ if (!lhs_base)
+ return false;
+
+ if (check_ref)
+ {
+ if (TREE_CODE (lhs_base) != MEM_REF
+ || TREE_OPERAND (lhs_base, 0) != base
+ || !integer_zerop (TREE_OPERAND (lhs_base, 1)))
+ return false;
+ }
+ else if (lhs_base != base)
+ return false;
+
+ rhs = get_ssa_def_if_simple_copy (rhs);
+
+ content->size = lhs_size;
+ content->offset = lhs_offset;
+ content->constant = is_gimple_ip_invariant (rhs) ? rhs : NULL_TREE;
+ content->next = NULL;
+
+ return true;
+}
+
/* Traverse statements from CALL backwards, scanning whether an aggregate given
in ARG is filled in with constant values. ARG can either be an aggregate
expression or a pointer to an aggregate. ARG_TYPE is the type of the
aggregate. JFUNC is the jump function into which the constants are
- subsequently stored. */
+ subsequently stored. AA_WALK_BUDGET_P points to limit on number of
+ statements we allow get_continuation_for_phi to examine. */
static void
-determine_locally_known_aggregate_parts (gcall *call, tree arg,
- tree arg_type,
- struct ipa_jump_func *jfunc)
+determine_known_aggregate_parts (gcall *call, tree arg,
+ tree arg_type,
+ struct ipa_jump_func *jfunc,
+ unsigned *aa_walk_budget_p)
{
- struct ipa_known_agg_contents_list *list = NULL;
+ struct ipa_known_agg_contents_list *list = NULL, *all_list = NULL;
+ bitmap visited = NULL;
int item_count = 0, const_count = 0;
+ int ipa_max_agg_items = PARAM_VALUE (PARAM_IPA_MAX_AGG_ITEMS);
HOST_WIDE_INT arg_offset, arg_size;
- gimple_stmt_iterator gsi;
tree arg_base;
bool check_ref, by_ref;
ao_ref r;
- if (PARAM_VALUE (PARAM_IPA_MAX_AGG_ITEMS) == 0)
+ if (ipa_max_agg_items == 0)
return;
/* The function operates in three stages. First, we prepare check_ref, r,
ao_ref_init (&r, arg);
}
- /* Second stage walks back the BB, looks at individual statements and as long
- as it is confident of how the statements affect contents of the
- aggregates, it builds a sorted linked list of ipa_agg_jf_list structures
- describing it. */
- gsi = gsi_for_stmt (call);
- gsi_prev (&gsi);
- for (; !gsi_end_p (gsi); gsi_prev (&gsi))
- {
- struct ipa_known_agg_contents_list *n, **p;
- gimple *stmt = gsi_stmt (gsi);
- HOST_WIDE_INT lhs_offset, lhs_size;
- tree lhs, rhs, lhs_base;
- bool reverse;
-
- if (!stmt_may_clobber_ref_p_1 (stmt, &r))
- continue;
- if (!gimple_assign_single_p (stmt))
- break;
+ /* Second stage traverses virtual SSA web backwards starting from the call
+ statement, only looks at individual dominating virtual operand (its
+ definition dominates the call), as long as it is confident that content
+ of the aggregate is affected by definition of the virtual operand, it
+ builds a sorted linked list of ipa_agg_jf_list describing that. */
- lhs = gimple_assign_lhs (stmt);
- rhs = gimple_assign_rhs1 (stmt);
- if (!is_gimple_reg_type (TREE_TYPE (rhs))
- || TREE_CODE (lhs) == BIT_FIELD_REF
- || contains_bitfld_component_ref_p (lhs))
- break;
-
- lhs_base = get_ref_base_and_extent_hwi (lhs, &lhs_offset,
- &lhs_size, &reverse);
- if (!lhs_base)
- break;
+ for (tree dom_vuse = gimple_vuse (call); dom_vuse;)
+ {
+ gimple *stmt = SSA_NAME_DEF_STMT (dom_vuse);
- if (check_ref)
+ if (gimple_code (stmt) == GIMPLE_PHI)
{
- if (TREE_CODE (lhs_base) != MEM_REF
- || TREE_OPERAND (lhs_base, 0) != arg_base
- || !integer_zerop (TREE_OPERAND (lhs_base, 1)))
- break;
+ dom_vuse = get_continuation_for_phi (stmt, &r, *aa_walk_budget_p,
+ &visited, false, NULL, NULL);
+ continue;
}
- else if (lhs_base != arg_base)
+
+ if (stmt_may_clobber_ref_p_1 (stmt, &r))
{
- if (DECL_P (lhs_base))
- continue;
- else
+ struct ipa_known_agg_contents_list *content
+ = XALLOCA (struct ipa_known_agg_contents_list);
+
+ if (!extract_mem_content (stmt, arg_base, check_ref, content))
break;
- }
- bool already_there = false;
- p = get_place_in_agg_contents_list (&list, lhs_offset, lhs_size,
- &already_there);
- if (!p)
- break;
- if (already_there)
- continue;
+ /* Now we get a dominating virtual operand, and need to check
+ whether its value is clobbered any other dominating one. */
+ if (content->constant
+ && !clobber_by_agg_contents_list_p (all_list, content))
+ {
+ struct ipa_known_agg_contents_list *copy
+ = XALLOCA (struct ipa_known_agg_contents_list);
- rhs = get_ssa_def_if_simple_copy (rhs);
- n = XALLOCA (struct ipa_known_agg_contents_list);
- n->size = lhs_size;
- n->offset = lhs_offset;
- if (is_gimple_ip_invariant (rhs))
- {
- n->constant = rhs;
- const_count++;
+ /* Add to the list consisting of only dominating virtual
+ operands, whose definitions can finally reach the call. */
+ add_to_agg_contents_list (&list, (*copy = *content, copy));
+
+ if (++const_count == ipa_max_agg_items)
+ break;
+ }
+
+ /* Add to the list consisting of all dominating virtual operands. */
+ add_to_agg_contents_list (&all_list, content);
+
+ if (++item_count == 2 * ipa_max_agg_items)
+ break;
}
- else
- n->constant = NULL_TREE;
- n->next = *p;
- *p = n;
+ dom_vuse = gimple_vuse (stmt);
+ }
- item_count++;
- if (const_count == PARAM_VALUE (PARAM_IPA_MAX_AGG_ITEMS)
- || item_count == 2 * PARAM_VALUE (PARAM_IPA_MAX_AGG_ITEMS))
- break;
- }
+ if (visited)
+ BITMAP_FREE (visited);
/* Third stage just goes over the list and creates an appropriate vector of
- ipa_agg_jf_item structures out of it, of sourse only if there are
+ ipa_agg_jf_item structures out of it, of course only if there are
any known constants to begin with. */
if (const_count)
}
}
+
/* Return the Ith param type of callee associated with call graph
edge E. */
jf->m_vr = ipa_get_value_range (type, min, max);
}
-/* Assign to JF a pointer to a value_range just liek TMP but either fetch a
+/* Assign to JF a pointer to a value_range just like TMP but either fetch a
copy from ipa_vr_hash_table or allocate a new on in GC memory. */
static void
|| !ipa_get_jf_ancestor_agg_preserved (jfunc))
&& (AGGREGATE_TYPE_P (TREE_TYPE (arg))
|| POINTER_TYPE_P (param_type)))
- determine_locally_known_aggregate_parts (call, arg, param_type, jfunc);
+ determine_known_aggregate_parts (call, arg, param_type, jfunc,
+ &fbi->aa_walk_budget);
}
if (!useful_context)
vec_free (args->polymorphic_call_contexts);
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